A constant velocity joint can be in the form of a counter track joint. Counter track joints comprise an even number of pairs of tracks. The first half of said pairs of tracks opens towards the aperture end of the outer joint part and the other half of said pairs of tracks opens towards the attaching end of the outer joint part. The pairs of tracks of the first and of the second type are arranged so as to alternate in the circumferential direction. The number of the pairs of tracks is an even number, more particularly amounts to 6, 8 or 10.
US 2007/01 1 1806 A1, corresponding to WO 2006/048032 A1, proposes a counter track joint of said type. The ball tracks—which in the central joint plane of an aligned joint, open towards the attaching end—at the attaching end, comprise a first arched portion with a small radius; in the region of the central joint plane, they comprise a second arched portion with a greater radius; and at the aperture end, they comprise a third arched portion which, relative to the second arched portion, comprises an opposed direction of curvature. The ball tracks which, in the central joint plane of the aligned joint, widen towards the aperture end, according to a first embodiment, comprise the same radius along the entire length of the ball tracks; or according to a second embodiment, they comprise an arched portion which, with a uniform radius, extends from the attaching end beyond the central joint plane and which, at the aperture end, is adjoined by a counter radius or, according to a third embodiment, they comprise an arched portion which, with the same radius, extends from the attaching end beyond the central joint plane and which, at the aperture end, is adjoined by a tangent.
From EP 1 656 509 B1, corresponding to WO 2005/028895 A1, there is known a counter track joint wherein it is proposed that the ball tracks which, in an aligned joint, in the central joint plane, extend from the aperture end to the attaching end, extend in an S-shaped way, wherein the centre line of said ball tracks in the outer joint part, towards the attaching end, deviates from a reference radius radially inwardly, and, towards the aperture end, deviates from said reference radius radially outwardly. As a result of said track shape of the ball tracks opening in an aligned joint in the central joint plane towards the attaching end, there is achieved an increase in the maximum articulation angle. The ball tracks which, in an aligned joint in the central joint plane, widen from the attaching end towards the aperture end, comprise a circular arch with a uniform radius from the attaching end to the central joint plane, which circular arch, at the aperture end, is adjoined by a tangent.
US 2010/0323802 A1, corresponding to WO 2008/080709, proposes a further counter track joint. The ball tracks opening in an aligned joint in the central joint plane from the aperture end to the attaching end extend in an S-shaped way. The ball tracks which widen in an aligned joint in the central joint plane from the attaching end to the aperture end extend in an S-shaped way and are composed of a rear arched portion with a large radius; in the region of the central joint plane, they comprise a central arched portion with a smaller radius as well as an arched portion at the aperture end, which arched portion, relative to the central arched portion, extends in the opposed direction of curvature. The ball cage comprises an outer spherical face with an internally spherical centre, wherein the externally spherical centre and the internally spherical centre are arranged so as to be offset relative to one another. As a result of this counter track joint design there is achieved a thicker cage diameter which leads to a greater strength and to deeper track run-outs at the attaching end, which, in turn, leads to a longer service life.
In the above-mentioned counter track joints, the ball tracks which, in an aligned condition of the counter track joint, open in the central joint plane towards the attaching end are curved radially inwards. Thus, the wrap angles of the ball tracks around the balls in the inner joint part and in the outer joint part are more aligned to one another and thereby enhanced.
In particular, in the case of counter track joints with six balls, it is difficult to achieve a reliable cage control combined with a low-noise characteristic because when the joint is in operation, only a total of three balls act on the cage in one direction, only some of which, under articulated conditions, provide a control function relative to the cage.